I have a speedport w925v router on which I have sinus 302i base with 5 handsets attached, the base is connected to the isdn port but the telephone has been changed to voip. My printer is an     hp officejet 6970 pro which has an analog fax which I would like to attach to my router. The instructions for the printer indicate I need a special adapter to attach an analog printer to  a router configured with a digital voip telephone. is true? If so, what do I need to do- and how. If not how do I attach the fax- if it is at all possible.